✔ 最佳答案
When all else has failed.
A bomb might break the asteroid into 2 or more pieces. It would be far better to have 10 smaller impacts spread over a few hours, than one large impact.
Each of the smaller impacts may well be survivable, whereas the single large impact may be an extinction event. Besides, depending on how the asteroid fragments, a significant portion of it may be in tiny pieces that would burn up in the atmosphere.
Hey ... before going for a nuclear solution, we'd really need a "new clear" policy on bombs in space.